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J S Haskill

Publications and source records attributed to J S Haskill.

87 records · Page 5Linked to original sources

In vitro and in vivo studies of the immune response to sheep erythrocytes using partially purified cell preparations.

The BSA density-gradient technique for separating mouse spleen cells into partially purified populations has been used to compare the responsiveness of such populations to SRBC using in vivo and in vitro techniques. Two major populations were distinguished, one of which responded very well in vivo with an exponential dose response and poorly in vitro (fraction 3), and another which responded in vivo and in vitro with a linear dose response (fraction 2). A light density, radiation-resistant component was identified which markedly stimulated the response of fraction 3 in vitro, and a density gradient profile was obtained for this cell which did not correspond with a macrophage profile. A high density, radiation-sensitive cell was identified which stimulated the response of PFC precursors in lighter regions of the gradient. The activity of this cell could be replaced using thymus cells. A density profile for the PFC precursor cell was obtained by assaying small numbers of spleen cell fractions in the presence of an excess of the two auxiliary cell types.

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Density distribution analysis of antigen-sensitive cells in the rat.

Analysis of the cell populations capable of initiating a response to sheep and horse erythrocyte antigens has been carried out by means of equilibrium density gradient centrifugation. The results indicate that there are at least six distinguishable AS cell populations for sheep erythrocytes, but only three for horse erythrocytes in the spleen of the Lewis rat. Evidence is presented for the existence of metabolic, physiological, and immunological differences among these populations. It is suggested that at least one population of AS cells responds only to the specific antigen and at least one other population is sensitive to stimulation by a broad range of antigens. It is assumed that the difference between these two AS cells results from a process of differentiation of AS cells primed into DNA synthesis by antigen stimulation.

Animals↗